Stoker



June 9. P. A. KETCHPEL 3,

sxoxma Original Filed Aug. 2, 1934 3 Sheets-Sheet 1 IN VEN TOR. PA (/1.A. KETCHPEL s am REDUGEI? ATTORNEY.

June 3, 1941. p A. K H EL 2,243,962

STOKER 1 Original Filed Aug. 2, 1954 3 Sheets-Sheet 2 INVENTOR. PA UL A.K E TCHPEL ATTORNEY,

June 3, 1941.

P. A. KETCHPEL.

STOKER Original Filed Aug. 2, 1934 I5 Sheets-Sheet 3 ATTORNEY.

Patented June 3, 1941 STOKER Paul A. Ketchpel, West Englewood, N. J.,assignor' to The Standard Stoker Company, Inc., a. corporation ofDelaware Original application August 2, 1934, Serial No. 738,039.Divided and this application January 30, 1936, Serial No. 61,518.Renewed September 29, 1939 21 Claims.

This application is a division of my co-pending application, Serial No.738,039, filed August 2, 1934, for Stoker.

My invention relates generally to automatic furnaces, and moreparticularly to small furneces such as are employed in the heating ofdwellings, apartment houses and greenhouses.

One object of my invention resides in the provision, in furnaces of thetype described, of a novel grate shaking arrangement.

Another object of my invention resides in the novel construction andarrangement of means for removing the ash from furnaces of the typedescribed.

Still another object of my invention resides in the provision infurnaces of the type described, of an improved and novel combination andarrangement of stoking, grate shaking and ash removal means, that issimple in construction, cheap to manufacture, and highly efficient inoperation.

' To the above and other ends the invention consists in the arrangementof parts and in their relation and association one with the other or incombination as hereinafter described and as illustrated in theaccompanying drawings, in which.

Fig. 1 is a vertical sectionalview of a furnace room showing a furnaceand stoker therefor in elevation with parts broken away and with thenovel grate shaking arrangement and ash removing device shown appliedthereto;

Fig. 2 is a view of the furnace in central vertical section with thestoker, grate shaker and ash removing device applied thereto and shownpartly in elevation and partly in section;

Fig. 3 is a sectional plan view through the furnace and bin with thestoker shown in elevation;

Fig. 4 is a vertical central section through the lower portion of thefurnace with a modified form of ash conveyor applied thereto and shownin similar section; and Fig. 5 is a sectional view on the line 5-5 ofFig. 4.

Referring now to Figs. 1 to 3, inclusive, of the drawings, whichillustrate one embodiment of the invention, a furnace room is designatedby the I9 is arranged to permit manual and stoker firing through thefiring opening 11.

It will be understood as the description proceeds that the invention isnot limited to the particular relation of the bin l4 and the furnace l3illustrated, since the bin may occupy any one of a number of positionsaround the furnace and may be nearer to it or farther away. As shown,the bin I4 is at one side of the furnace l3 and a stoker elevatingconduit 20 extends upwardly and laterally from a position near thebottom of the bin I4 through the bin wall 2| and terminates a shortdistance above the firing opening ll of the furnace l3. A screw conveyor26 is mounted in the elevating conduit 20 and is arranged to be drivenfrom its upper end through the drive shaft 29. cates with the upper endof the elevating conduit 20 and curves downwardly toward the firingopening ll. At its lower end the conduit 40 communicates with a chute42, that curves down wardly and communicates with the firing opening l1through the opening 43 in the door 19, discharging fuel into thefurnace. The details of construction of the stoker are not describedhere since they form the basis of my application Serial No. 738,039, ofwhich the present application is a division.

In order to prevent the accumulation of ashes on the grates below thefuel bed, which would hinder the natural draft from passing through thefuel bed, a novel grate shaking arrangement is provided. The lower endof the shaft of the screw conveyor 26 extends into the compartment 39and is connected with the speed reducer 55 by the universal joint 56.Movement is transmitted from the speed reducer 55 to the drive shaft 51through the universal joint 58. The drive shaft 51 extends forwardlyfrom the speed reducer through a housing 59, which extends beneath thefioor of the fuel bin, to the furnace l3 and is connected at its forwardend to the shaft by a universal connection 6|.

The stoker conveyor screw 26 and the shaft 51 are angularly related bothin a vertical plane as shown in Fig. 1 and in a horizontal plane asshown in Fig. 3. In order to reduce the angularity, considered in avertical plane, at the universal joint 58 between the shaft of theconveyor screw 25 and the shaft of the speed reducer 55, the speedreducer is mounted at an angle to the horizontal, as shown in Fig. 1. Toobtain the most favorable angle, considered in a horizontal plane, atthe universal joints 56 and 58betwcen the shaft of the conveyor screw 26and the shaft The conduit 40 communi- !l with the shafts of the speedreducer, the speed reducer is located so that the angle between theshaft 51 and the speed reducer shaft to which it is connected isapproximately equal to the angrates an oscillating motion. A handle 68is pro-' vided for manually shaking the grate I8 independently of thestoker mechanism if it is necessary at any time to fire the furnacemanually. To permit of adjustment of the amount that the eccentric 84rocks the grate I6, 9. link'BS is provided connecting the legs 65 and65. which has holes III of varied spacing to adjust the lost motionbetween the eccentric 64 and the legs 65 and 68. The lost motion betweenthe eccentric 64 and the legs 65 and 68 permits the grate to remainstationary for a. period of time at each of the limits of itsoscillation. Since the grates remain in rocked position for a space oftime, the amount of air drawn up through the grates is increased. Thisis of particularimportance when the openings between the grates arerestricted as in installations adapted for burning of fuel of smallsize. It is evident that the air supply to the firebox may be increasedor decreased by increasing or decreasing the lost motion between theeccentric and the legs 65 and 68.. A protecting shield or plate II maybe attached to the legs 85 and 86 to prevent ashes from dropping on theeccentric 64 and from getting in the bearing 82.

The rate at which the grates are oscillated is determined by the rate ofspeed of the stoker conveyor screw 28, since they are operativelyconnected therewith through the shafts 60 and 51 and speed reducer 55.Thus, if the stoker is speeded up to produce heavier firing, the gratesare oscillated more rapidly to take care of the g eater amount of ashformed. I

A conduit including the trough-like portion I2 and the tubular portionI8 is mounted beneath the grate IE to receive the ashes fallingtherethrough and extends to the compartment 85. A slope sheet I3 fixedto the rear wall of the furnace in the ash pit 38 beneath the grate I8and another sheet I secured to the ash door.

I8 provide a self-cleaning arrangement in the by the screw conveyor 11through the conduit 18 and allowed to drop through the outlets I9 and 80into the ash containers 8| and 82. tainers are provided with dust prooflids 83 and 84 closely and telescopically fitting the outlets I9 and 80.To keep the ash containers out of sight and provide more floor space,they are disposed in the compartment 85 beneath the furnace room floor,this compartment being covered by the door 85a.

In Figs. 4 and 5 is shown a modified form of The ash con-.

the ash removing device, wherein means is provided for stopping the ashconveyor 86 after the ash receptacles have become filled, allowing theashes to accumulate in the trough 81 and ash pit 88. The ash conveyorconduit 89 has a hinged door or end cover BI that is pushed open by theaccumulation of ashes in the conduit 89 when the ash receptacles arefilled. Opening of the door 9| moves a catch 92 and releases the latch83 mounted on the same shaft as the bell crank 84, which by reason ofthe weight swings downward moving the rod 90 toward the left.

The rod 96 is connected with the lower end of a clutch yoke 91 which ispivotally mounted at I25 in a bracket 98 attached to the end plate 99.The yoke 91 engages the clutch member I00 which is slidably keyed on theshaft IOI. Normally the clutch member I00 is in engagement with acompanion clutch member I02 universally connected with and driven by theshaft I03; however, when the accumulation of ash at the end of theconduit 89 opens the door 8i releasing the latch 83 and causing the bellcrank 94 to move the shaft 86 to the left, the clutch members I00 andI02 are disengaged, as shown in Fig. 4, and operation of the ashconveyor screw 80 is stopped.

An alarm may be provided for indicating when the clutch members I00 andI02 have become disengaged and have thereby interrupted the operation ofthe ash conveyor 80. A clapper H4 is pivotally attached at one end tothe clutch member I02, as at I28, and rotates therewith. Looking at Fig.5, the clutch member I02 rotates in a counterclockwise direction and theclapper II4, during the ascending portion of its movement, because ofits pivotal connection I25, rests against the hub portion of the clutchmember I02. During the descending portion of its movement the clapper H4becomes overbalanced and swings downwardly about its pivotal connectionI20 striking the bell H5. The bell H5 is mounted on the yoke 81 belowthe pivotal connection I25 and moves into the path of the clapper II4when the yoke is moved by the rod 90 in a. direction to shift the clutchmember I00 out of engagement with the clutch member I02.

From the foregoing description it will be apparent that the novelcombination and arrangement of parts together with the particularstructure of various elements permits the maintenance of a shallow levelfuel bed that is continuous]? being replenished. The fuel feedingportion of my automatic furnace is arranged to spread fuel over thefurnace grate continuously in a thin even stream; the grate shakingportion, since its operation is synchronized with the stoker, shakes theashes from the fire as rapidly as the fuel is consumed; and, the ashremoving portion contmuously conveys the ashes away. As a result, a thineven fire, free from ashes, may be constantly maintained. 1

A shallow fire burns at a much higher temperature and more nearlyresembles gas and oil fires, because the natural draft of the chimneycan cause the air to pass up through the fire bed and produce a morenearly perfect combustion of the fuel than is possible with a deep fireand a forced draft. Also an increase in the useful heating surface ofthe furnace is gained over those types of stokers that carry a deep firebed, since in the latter the fire bed smoulders at a relatively lowtemperature and usually includes an accumulation of ash. Tests have alsoshown that the flue gases taken from a furnace having a comparativelythin and hot fire contain a great deal lessxunburned carbon than theflue gases taken from a slow smouldering fire, such as is the conditionin deep fire beds.

I claim:

1. In a furnace. room having a floor, a furnace provided with a grateand an ash chamber therebeneath, a trough-like depression in said floorcommunicating with said ash chamber, a fuel bin, the floor of said fuelbin being on a level with said furnace room floor, a stoker including aconveyor screw arranged to convey fuel from said bin to the furnace,said conveyor screw having an extended shaft projecting beneath thelevel of said floor, a screw conveyor in said trough-like depression forconveying ash, a housing beneath thefuel bin floor and a drive shaft insaid housing operatively connected at one end below the level of saidfloor with the stoker conveyor screw shaft extension and at its otherend with the ash conveyor screw.

2. In a furnace room having a floor, a furnace, a trough-like depressionin said fioor beneath the furnace arrangedto receive ash from thefurnace, an ash conveyor mounted in said depres sion, a fuel bin, thefloor of said fuel bin being on a level with said furnace room fioor, astoker including a conveyor screw arranged to convey fuel from said binto the furnace, a compartment beneath the fuel bin fioor, the shaft ofsaid stoker conveyor screw extending into said compartment,

a housing beneath the fuel bin floor communicating at one end with saidcompartment and at the other end with said trough-like depression, adrive shaft in said housing for said ash conveyor and gearing insaidcompartment operatively connecting said stoker screw conveyor shaftand said drive shaft. r

3. In a furnace, a grate provided with a grate shaker bar, an ash pitbeneath said grate, means including a screw conveyor for conveying ashesfrom said pit, a yoke rigidly secured to said grate shaker bar, saidyoke having a pair of leg members extending downwardly, one on each sideof the axis of said screw conveyor, an eccentric mounted to rotate withsaid screw conveyor and arranged to alternately engage said leg membersfor rocking said grates first' in-one direction and then in the oppositedirection.

4. In a furnace, a grate provided with a grate shaker bar, an ash pitbeneath said grate, means including a screw conveyor for conveying ashesfrom said pit, a yoke rigidly secured to said grate shaker bar, saidyoke having a pair of leg members extending downwardly, one on each sideof the axis of said screw conveyor, an eccentric mounted to rotate withsaid screw conveyor and arranged to alternately engage said leg membersfor rocking said grates first in one direction and'then in the oppositedirection, said leg members being spaced such a distance apar-tthat theeccentric will intermittently engage said leg members,

5. In a furnace room having a floor, a-furnace and a. fuel bin, a firingopening in said furnace, a stoker fuel conveyor extending upwardly. fromthe bottom of said bin to the firing opening in said furnace, acompartment beneath the floor of said fuel bin, said fuel conveyorhaving a shaft extending through the floor of said bin into saidcompartment, an ash conveyor beneath said furnace, said ash conveyorhaving a shaft extending into said compartment, a speed reducer in saidcompartment having a shaft universally connected with said stokerconveyor shaft and a second shaft universally connected with said ashconveyor shaft, said speed reducer being mounted at such an angle thatthe angle between its first named shaft and the stoker conveyor shaft isapproximately equal to the angle between i-ts second named shaft and theash conveyor shaft.

6. In a furnace, a grate, an ash chamber beneath said grate, a trougharranged to receive the ashes from said chamber, a conveyor in saidtrough, mechanism associated with said conveyor for shaking said grate,the cross sectional area of said trough at its open mouth being lessthan the cross sectional area of said chamber, and a plurality ofupstanding plates mounted in said chamber forming a restricted openingin the lower portion of said chamber, one of said upstanding platesforming a shield for said grate shaking mechanism from the ash droppingfrom said grate.

7. In combination with a furnace having a grate, a stoker including afuel conveyor having a fuel receiving end in communication with a sourceof fuel supply and a fuel delivery end adjacent the furnace, means foroperating said fuel conveyor from its end adjacent the furnace. an ashconveyor beneath said grate for removing ashes from the furnace, meansoperatively connecting said ash conveyor with the fuel receiving end ofsaid fuel conveyor for operating the ash conveyor from the fuelconveyor, means operatively connected with said ash conveyor for shakingsaid grate, and means for rendering said grate shaking means and saidash conveyor inoperative independently of said fuel conveyor.

8. In a furnace, a grate provided with a grate shaker ban-an ash pitbeneath said grate, means for conveying ashes from said pit, a rotatablymounted eccentric, a common actuator for said ash conveyor andeccentric, and means operatively connected to said grate shaker bararranged to be engaged by said eccentric for rocking said grates firstin one direction and then in the opposite direction.

9. In combination with a furnace having a firing opening and a grate, astoker fuel conveyor leading from a source of fuel supply to the fir--ing opening in said furnace, an ash conveyor beneath said grate, saidfuel conveyor and said ash conveyor each having shaft extensionsterminating adjacent each other, power transmission means operativelyconnecting the adjacent ends of said shafts, said transmission meanshaving a shaft universally connected with said stoker conveyor shaft anda second shaft universally connected with said ash conveyor shaft, saidtransmission means being mounted so that the angle between its firstnamed shaft and the stoker conveyor shaft is approximately equal to theangle between its second named shaft and the ash conveyor shaft.

10. In combination with a furnace having a grate, a stoker for conveyingfuel from a source of supply to the furnace and delivering it onto saidgrate, an ash pit beneath said grate, an ash receptacle, means forconveying the ashes from said pit to said ash receptacle, means foroperating said stoker, a drive connection between said stokerand saidash conveyorfor operating the latter, means operatively associated withsaid ash conveyor for shaking said grate, and means for automaticallyrendering both said ash conveyor and said grate shaking meansinoperative when I said receptacle is filled, without interruptingoperation of said stoker.

11. In combination with a furnace having a grate, a stoker for conveyingfuel from a source of supply to the furnace and delivering it onto saidgrate, an ash pit beneath said. grate, an ash receptacle, means forconveying the ashes from said pit to said ash receptacle, means foroperating said stoker, a drive connection between said stoker and saidash conveyor for operating the latter from said stoker, and means forautomatically rendering said ash conveyor inoperative when saidreceptacle is filled, without interrupting operation of said stoker.

12. In combination with a furnace having a grate, a stoker for conveyingfuel from a source of supply to the furnace and delivering it onto saidgrate, an ash pit beneath said grate, conveying means for removing ashesfrom said pit,

means for operating said stoker, a drive connection between said stokerand said ash conveyor for operating the latter, said drive connectionincluding a clutch, and means responsive to an accumulation of asharranged to disengage said clutch for rendering said ash conveyorinoperative without interrupting operation of said stoker.

13. In a furnace, a grate provided with a grate shaker bar, an ash pitbeneath said grate, conveying means for removing, ashes from said pit,means securely attached to said grate shaker bar including a pair ofdepending members, one on each side of said conveying means, aneccentric mounted to rotate with said conveying means and arranged toalternately engage said depending members for rocking said grates firstin one di rection and then in the opposite direction.

14. In a furnace, a grate provided with a grate shaker bar, an ash pitbeneath said grate, conveying means for removing ashes from said pit,means attached to said grate shaker bar including a pair of dependingmembers, one on. each side of said conveying means, an eccentric mountedto rotate with said conveying means and arranged to alternately engagesaid depending members for rocking said grates first in one directionand then in the opposite direction, said depending members being mountedfor adjustment a desired distance from said eccentric forvarying therocking movement of said grates.

15. In combination, a furnace having a firing opening in an upright wallthereof, a fuel bin at one side of said furnace, a stoker conduitincluding a fuel conveyor extending downwardly and laterally withrespect to said furnace from said firing opening to the bottom of saidfuel bin, an ash conveyor extending laterally with respect to thefurnace from the lower portion of the furnace to a point remotetherefrom, said fuel conveyor and said ash conveyor each having shaftextensions terminating adjacent each other, means operatively connectingthe adjacent ends of said shafts including speed reducing means foroperating said ash conveyor at a slower speed than said fuel conveyor,and means operatively connected with the upper end of said fuel conveyorfor actuating said fuel conveyor and said ash conveyor.

16. In combination with a furnace having a grate, a stoker fuel conveyordelivering fuel from a source of fuel supply to the furnace, means foroperating said stokerconveyor, an ash conveyor beneath said grate forremoving ashes from the furnace, means operatively connecting said ashconveyor with said stoker conveyor for operating the ash conveyor fromthe stoker conveyor, and means for rendering said ash conveyorinoperative independently of said stoker conveyor.

17. In combination with a furnace having a grate, a stoker fuel conveyordelivering fuel from a source of fuel supply to the furnace, means foroperating said stoker conveyor, an ash conveyor beneath said grate forremoving ashes from the furnace, means operatively connecting said ashconveyor with said stoker conveyor for operating the ash conveyor fromthe stoker conveyor, means operatively connected 'with said ash conveyorfor shaking said grate, and means for rendering said grate shaking-meansand said ash,

conveyor inoperative independently of said stoker conveyor.

18. In combination with a furnace having a grate, a stoker fuel conveyordelivering fuel from a source of fuel supply to the furnace, means foroperating said stoker conveyor, means for shaking said grate, meansoperatively connecting said grate shaking means with said stokerconveyor for operating the grate shaking means from the stoker conveyor,and means for rendering said grate shaking means inoperativeindependently of said stoker conveyor.

19. In a furnace, a grate, an ash compartment beneath said grate, meansfor conveying ashes from said compartment, a rotatably mounted cam, acommon actuator for said ash conveyor and means operatively connected tosaid grate and engaged by said cam for moving said grate first in onedirection and then in the opposite direction. I

20. In a furnace, a grate, an ash compartment beneath said grate,conveying means for removing ashes from said compartment, said gratebeing provided with a pair of depending members, one on each side ofsaid conveying means, and means operatively associated with saidconveying -means arranged to alternately engage said depending membersfor rocking said grates first in one direction and then in the oppositedirection.

21. In a furnace, a grate, an ash compartment beneath said grate,conveying means for removing ashes from said compartment, means securelyattached to said grate including a pair of depending members, one oneach side of said conveying means, means mounted to rotate with saidconveying means arranged to alternately engage said depending membersfor rocking said grate first in one direction and then in the oppositedirection.

PAUL A. KETCHPEL.

